Scepticism 9780773581975

Table of contents :
Cover
Contents
Acknowledgements
Introduction: The whimsical condition of mankind
1 Scepticism and knowledge
2 The legacy of Socrates
3 Demons, doubt and common life
4 Transcendental meditations
5 Un/natural doubts
6 Internalisms and externalisms
Notes
Bibliography
Index
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
W
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Citation preview

Scepticism

Central Problems of Philosophy Series Editor: John Shand This series of books presents concise, clear, and rigorous analyses of the core problems that preoccupy philosophers across all approaches to the discipline. Each book encapsulates the essential arguments and debates, providing an authoritative guide to the subject while also introducing original perspectives. This series of books by an international team of authors aims to cover those fundamental topics that, taken together, constitute the full breadth of philosophy. Published titles Free Will Graham McFee

Scepticism Neil Gascoigne

Knowledge Michael Welbourne

Truth Pascal Engel

Relativism Paul O'Grady

Universals J. P. Moreland

Forthcoming titles Action Rowland Stout

Ontology Dale Jacquette

Analysis Michael Beaney

Paradox Doris Olin

Artificial Intelligence Matthew Elton & Michael Wheeler

Perception Barry Maund

Causation and Explanation Stathis Psillos

Rights Jonathan Gorman

Meaning David Cooper

Self Stephen Burwood

Mind and Body Robert Kirk

Value Chris Cherry

Modality Joseph Melia

Scepticism Neil Gascoigne

McGill-Queen;s University Press Montreal & Kingston • Ithaca

© Neil Gascoigne 2002 ISBN 0-7735-2476-2 (bound) ISBN 0-7735-2477-0 (paper) This book is copyright under the Berne Convention. No reproduction without permission. All rights reserved. Published simultaneously outside North America by Acumen Publishing Limited McGill-Queen's University Press acknowledges the financial support of the Government of Canada through the Book Publishing Development Program (BPIDP) for its activities. National Library of Canada Cataloguing in Publication Gascoigne, Neil, 1962Scepticism / Neil Gascoigne. (Central problems of philosophy) Includes bibliographical references and index. ISBN 0-7735-2476-2 (bound).—ISBN 0-7735-2477-0 (pbk.) 1. Scepticism. I. Title. II. Series. B837.G38 2003

149'.73

C2002-904419-7

Designed and typeset by Kate Williams, Abergavenny. Printed and bound by Biddies Ltd., Guildford and King's Lynn.

Contents

1

Acknowledgements

vi

Introduction: The whimsical condition of mankind

1

Scepticism and knowledge

6

2 The legacy of Socrates

31

3 Demons, doubt and common life

68

4 Transcendental meditations

100

5 Un/natural doubts

133

6 Internalisms and externalisms

165

Notes Bibliography Index

198 207 213

Acknowledgements

My fascination with philosophical scepticism began when I was a graduate student in the Department of History and Philosophy of Science at the University of Cambridge. From that period I am indebted to Nick Jardine for encouraging that and other more arcane interests. During our time together at Cambridge I benefited greatly from conversations with Julia Borossa, Mark Collier and Tim Thornton, and have the good fortune of continuing to do so. Tim offered probative comment and criticism on an earlier draft of this work, as did Katerina Deligiorgi and two anonymous readers for Acumen. Jonathan Derbyshire read through several drafts of several chapters, all of which are the better for his philosophically scrupulous attentions. The manuscript was revised and completed whilst I was on sabbatical at the University of Chicago. I would like to thank Robert Pippin, Chair of the Committee on Social Thought, for hosting my visit, and Aaron Lambert and the faculty and graduate students of the philosophy department for making it a pleasurable and stimulating one. The visit to Chicago was suggested to me by a fellow sceptic, Andrea Kern, and made possible through the cooperation of my colleagues in the philosophy department at Anglia, among whom I am grateful in particular to my longstanding partner in departmental crime, Alison Ainley. My former colleague Herr Professor Andrew Bowie has been a source of philosophical stimulation since I first started teaching. Above all I want to thank Rachel for her insightful comments on the (near) final draft and for the support and encouragement that has kept me going during the time it has taken to bring this project to completion.

Introduction: The whimsical condition of mankind

For here is the chief and most confounding objection to excessive scepticism, that no durable good can ever result from it; while it remains in its full force and vigour . . . When [the sceptic] awakes from his dream, he will be the first to join in the laugh against himself, and to confess, that all his objections are mere amusement, and can have no other tendency than to show the whimsical condition of mankind, who must act and reason and believe; though they are not able, by their most diligent inquiry, to satisfy themselves concerning the foundation of these operations, or to remove the objections, which may be raised against them. (Hume 1975: 159-60) It seems reasonable to open a book such as this with a simple question: What is scepticism? According to Webster's, it is "an attitude of doubt or disposition toward incredulity in general or in regard to something particular". So scepticism relates to doubt; but what is it to 'doubt' or to have a 'doubting attitude'? Mention scepticism to anyone who has been subjected to an introductory course on 'The Problems of Philosophy' and they will probably recall that there are a number of arguments that seem to show that we can doubt, and therefore don't know, many if not all of the things we claim to know. As such, what it is to doubt is associated with certain sorts of thought-experiments like the idea that right now you or I might be dreaming, or a disembodied brain floating around in a vat of nutrients linked up to a supercomputer.

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These imagined possibilities, once the preserve of students of philosophy, have entered the mainstream imagination through films like The Matrix and Existenz, which in turn serve to dramatize how difficult they are to dismiss. As you read this you might find it hard to believe that you are asleep or an envatted brain, but do you know that you aren't? Are you certain! Do you have any evidence to the contrary? Since these possibilities suggest that your sensory experience would be the same as if you were awake, what kind of evidence could convince you that they don't in fact obtain? And if you can't rule them out, can you really claim that you know anything at all about the external world? Once we adopt a certain sort of attitude towards our everyday empirical claims, we view them in a very different light and they start to look very precarious indeed. I'm going to call this particular way of thinking about ourselves - almost as if we were 'outside' our own minds, looking down on ourselves - the 'theoretical attitude'. Trying to understand how the theoretical attitude relates to scepticism will be one of the main themes in this book, so there's no need to discuss it in detail now. Nevertheless, to get a preliminary feel for how odd it is, imagine the following situation. You the reader have somehow managed to discover that you're neither an envatted brain nor dreaming. Since your sensory experience would be the same even if you were an envatted brain, your discovery cannot be empirical in nature - it can't for example be the case that you've just seen that you are embodied. So your discovery must be non-empirical in nature: something that you have arrived at as a result of your philosophical sophistication. Since you know that you're not a brain in a vat, and that you can therefore trust your sensory experience, you know that your friend Tim isn't a brain in a vat either. Tim, however, has never read any philosophy and never goes to the cinema and it has never even occurred to him that he might be dreaming or an envatted brain. Given such an eventuality, can Tim be said to know that he's not an envatted brain? If not, can he be said to know what you know; namely, that he's got two hands? It's not odd to imagine a situation where you know something about Tim that he doesn't know, but it does seem strange to conclude that you know he's got hands but he doesn't! This seems like a counter-intuitive and even rather elitist conclusion to arrive at, but it shows that once one adopts the theoretical

I N T R O D U C T I ON

3

attitude, scepticism presents epistemology with a theoretical task: to demonstrate that knowledge of the external world is possible and in general possessed by all, regardless of their philosophical sophistication. Reflecting on the possibility that we might be envatted brains is not the only way to raise sceptical doubts, however; and it is not even the most radical. Consider your most strongly held beliefs or most cherished forms of inference: how do you know that they are dependable? You may have seen the sun rise a hundred thousand times in your life, but does that give you a good reason for thinking that it will rise in the future? Even if you were an envatted brain it would be nice to think that you could rely on the vat-sun rising again, or on vat-beer not suddenly beginning to taste like vat-milk! The flip-side of this is that when you dismiss such thoughts, leave this book (or dream-book) aside, and re-embrace the contexts of everyday life, you will probably give scant thought to the question of whether or not you can trust inductive reasoning, nor dwell on the thought that you're an envatted brain. When we adopt what I'll call the 'practical attitude', with its encounters and negotiations with the world of objects and other people, theoretical attitude concerns about our dire epistemic situation seem quaint and carry little if any conviction. Indeed, in such contexts, theoretical attitude doubts would appear as invidious attempts to avoid responsibility: 'I can't take you to hospital because I don't know that you or anything else exist!' So far, then, we have identified two related characteristics of sceptical doubt. On the one hand it involves a peculiar sort of 'reflective withdrawal' from our practical attitude engagements with people and things in the world and the adoption of the theoretical attitude; on the other hand it carries no conviction. But if sceptical doubts really do have no effect on our practices then how do we account for the fact that they arise so naturally when we take up a certain attitude towards those practices? Shouldn't we be able to demonstrate why such doubts carry no conviction, and that there is therefore something unnatural about them? If we can't - if the alltoo-human activities of reasoning, believing and acting on those reasons and beliefs cannot be defended against such doubts - do we have the right to our practical attitude insouciance? What does this apparent 'insulation' of the practical attitude from the theoretical attitude tell us about what it is to act, reason and believe?

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These questions frame one set of responses to our enquiry into what it is to doubt or have a doubting attitude, and they will recur throughout this book. However, it is important to note that the split between the theoretical and practical attitudes is not as clear-cut as the questions suggest. After all, most people, including philosophers in 'normal' conversation, would also associate scepticism with something much more commonplace. In the way that 'philosophy' itself is often used to vaguely indicate a worldview or reflective standpoint, 'scepticism' in this sense suggests a particular state of mind or attitude towards some issue or other. It may often be negatively associated with expressions of cynicism, and perhaps even of suspicion, but there is also what is referred to as a 'healthy scepticism'. One might not always be doubting whether one is in fact really in love, treating others fairly, doing the right job or living the right kind of life, but these practical doubts don't seem nearly as removed from common life as doubting whether or not one is awake or can trust one's basic methods of reasoning. Equally, whereas in the realm of the everyday one might not doubt that one has a body, one might well find oneself being sceptical about a referee's decision or the diagnosis of some illnesses or the claims of a fellow scientist. Whether they involve moral deliberation, existential speculation, or scientific investigation, these doubts all involve taking up a reflective distance on a belief or activity in order to scrutinize it in a broader context that answers to our particular interests and projects. Moreover, whilst it's difficult to imagine what our lives would be like without them and at least the possibility of responding to them, this sort of doubt and its associated reflection does not appear to lead to the kind of disengagement we noted with the theoretical attitude. Practical attitude doubts seem to relate to context in a way that theoretical attitude doubts do not. We might call such an attitude fallibilistic: a reflective awareness that although we might have very good reasons for believing some things rather than others, those reasons do not secure an absolute certainty that puts them beyond the possibility of error. In part, then, the aim of this book is to investigate whether the varieties of sceptical doubt that we've loosely associated with the theoretical and practical attitudes are as remote from one another as at first blush appears to be the case. In addition to being an introduction to the formal problem scepticism presents to contemporary

INTRODUCTION

5

epistemologists, it is therefore also an enquiry into the relationship between philosophical reflection and the sort of reflection we associate with living a life characterized by a degree of critical selfawareness. What is of primary interest here is the history of scepticism, for this constitutes an elaboration of ways in which the relationship between philosophy, critical reflection and practical life has been understood. As such, the history of scepticism presents a focus for reflection that promises to shed a little light on the 'whimsical condition of mankind'. The task is to balance these two objectives: to get a sense of what importance scepticism has had for different philosophers at different periods, while providing the analytic tools needed to situate the problem as conceived by today's epistemologists. The methodological assumption of this book is that these aims are related - that one can better understand contemporary concerns, and see why various strategies to deal with them take the form they do, when one comes to appreciate how the character and perceived significance of scepticism has changed. At the same time, the genealogical element is not merely a disinterested survey of aged texts; the past takes on the significance it does because of the desire to understand our contemporary concerns, and offers the possibility of new ways of responding to them.

1

Scepticism and knowledge

Introduction

The aim of this chapter is to provide a preliminary introduction to the problem of scepticism as a contemporary epistemologist would see it; namely, as a problem that emerges when one adopts the theoretical attitude towards knowledge claims. In pursuit of this aim, the chapter has three main objectives: first, to enquire into what it is that the sceptic doubts and therefore discover to what aspect of our human self-understanding that doubt poses a threat; secondly, to examine two ways in which the sceptic goes about generating her doubt, the so-called 'argument from ignorance' and the Agrippan argument'; and finally, to provide a context from within which the threat of sceptical doubt and the ways in which it is generated can be seen to relate to the concerns of the contemporary epistemologist. In the fulfilment of these objectives I intend to motivate my claim that to understand sceptical doubt more fully we need to know something of its historical development. The task of epistemology

The central task of epistemology as many philosophers see it is summed up by the American philosopher Barry Stroud: We aspire in philosophy to see ourselves as knowing all or most of the things we think we know and to understand how all that knowledge is possible. We want an explanation, not just of this or that item or piece of knowledge, but of knowledge, or knowledge of a certain kind, in general. (1994: 296)

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We all claim to know lots of things and presumably aspire to know a lot more. It is important both to our self-understanding and to our understanding of others that knowledge has a value that sets it over and above mere opinion. Whenever we claim to know something or encounter someone making such a claim, we recognize that something is at stake: the claimant has represented himself or herself as satisfying whatever conditions make something a case of knowing. One of the responsibilities that goes along with that representation is to be able to offer reasons why this is a case of knowing and not just one of opinion. There is nothing mysterious about this; indeed, it is the most common of phenomena. I know that the Sears Tower is in Chicago. If asked how I know this, I might mention that I initially saw a picture of it in a travel guide and then go on to say that I have been to Chicago and seen it for myself. Perception, memory and testimony (I tend to trust the people who write travel guides) all contribute to an explanation of this particular item of knowledge, and there doesn't seem anything unsatisfactory about the reasons I give certainly nothing that we would look to philosophy to remedy. Contrasting with this, Stroud identifies a much more demanding aspiration. What we want, he suggests, is the assurance that our concept of knowledge is itself legitimate•; that creatures like us are entitled to think of ourselves as knowers, and that we aren't just deluding ourselves when we claim to know all the things we think we do. This assurance is to be gained by explaining how knowledge (or knowledge of a certain kind) is possible. On Stroud's account, then, the epistemological task is to demonstrate that our concept of knowledge is legitimate by explaining how knowledge is possible. Note that as these things are usually viewed this is a normative problem, not a descriptive one. It is not going to be answered by giving us facts about how we do or do not use the concept of knowledge; neither is it going to be answered by giving us a scientific account of, say, the nature of perception (since such an account would presuppose that scientific knowledge is possible). Rather, an answer must be in the form of an account that gives us reasons to believe we have a right to use the concept. Moreover, since the account is to be general, these reasons will not be tied to specific examples of knowing like those given in defence of my claim to know that the Sears Tower is in Chicago (perception

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etc.). The reasons that constitute any explanation of how knowledge or knowledge of a certain kind is possible are going to be relevant to all such claims to know, irrespective of whether they are about towers, trees or tentacles. In very general terms we might distinguish three responses to what Stroud identifies as the task of philosophy, what I'll call the heroic, the rejectionist and the sceptical. The heroic response is Stroud's own, and it provides a preliminary answer to the question 'what does the sceptic doubt?' What the sceptic doubts is that knowledge (or knowledge of a certain sort) is possible. On the heroic understanding of epistemology, scepticism is at the heart of enquiry because it is only by responding to the sceptic's doubts that it can be demonstrated that knowledge is indeed possible. The rejectionist response is to deny that showing how knowledge is possible is central to epistemological enquiry, and therefore to deny the centrality of sceptical doubt.1 To take a well-known example, the proponents of what is called 'naturalized epistemology' proceed on the assumption that knowledge claims are not irreducibly normative, and that knowledge does not in general stand in need of philosophical legitimation. Epistemology is therefore not a normative enquiry but an extension of the methods of the natural sciences. Despite divergent views on the importance of scepticism, the heroic and rejectionist responses are both part of the modern epistemological tradition. Indeed, as we'll see below, rejectionism can be viewed as a reaction to the perceived failure of epistemological heroism. The sceptical response derives from a far older tradition, and exhibits a different understanding of what scepticism is. It does not concern the direct question of whether knowledge is possible (although it is clearly related) so much as the question of whether it is possible to offer an account that shows us that knowledge is possible. Viewed from the perspective of the heroic response, the sceptic is a philosophical opponent who calls into question the possibility of knowledge by providing reasons for doubt. This sets the task for the heroic epistemologist: to give us reasons for thinking that these doubts are unwarranted, thereby entitling us to see ourselves as knowing what we think we know. From the perspective of the sceptical response, however, philosophical reasoning is the target the possibility of philosophical knowledge itself is called into question. In so far as both heroic and rejectionist epistemologists aspire

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to the possession of philosophical knowledge (pk), then, their theoretical activities attract the attention of the sceptic. To avoid confusion, we'll call this variety of scepticism p£-scepticism and reserve the name scepticism for what is of interest in traditional epistemology. We'll turn to the relationship between the heroic, rejectionist and sceptical responses at the end of this chapter. For the time being we'll restrict our attention to the variety of scepticism that presents a challenge to the heroic task by questioning the possibility of what we commonsensically understand as knowledge. The argument from ignorance

How then does the sceptic give us reasons for doubt about the possibility of knowledge? The answer in part depends on what kind of knowledge we're talking about. For most contemporary philosophers the kind of knowledge we'd particularly like to see ourselves as possessing is perceptual knowledge, what is usually referred to as knowledge of the external world. Right now I'm sitting in a library typing - I can see my new computer in front of me, feel the heat from the keyboard, smell the upholstery of the chair I'm in, hear the whirring of the air-conditioning, taste the chocolate in my mouth. I want to say that I know that I'm sitting wide awake in the library (or rather, I say that I am and that is taken as a claim to know). Here the sceptic casts doubt on the possibility of such knowledge by aiming to undermine my confidence in the cognitive status of my perceptual experiences. She points out that I might be dreaming; or perhaps even a disembodied brain, wired up to a supercomputer and floating around in a vat of nutrients. Both of these sceptical possibilities are seemingly consistent with my having exactly the same perceptual experiences as I'm having now, but in neither case would those experiences be reliable guides to what's really going on in the world. By invoking possibilities like these, the sceptic presents a challenge to the epistemologist who wants to show how knowledge of the external world is possible. How can it be, if I rely entirely on experience and yet what I experience is consistent with not knowing what I ordinarily take myself to know? And what applies to me, applies equally to you! This particular way of generating doubt can be usefully generalized in the form of an argument. Letting S stand

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for any subject, q for any empirical proposition (like Tm awake in the library' or 'I've got two hands') and sp for any of the sceptical possibilities mentioned (like 'S is an envatted brain'), we have the following: S doesn't know that not-sp If S doesn't know that not-sp, then S doesn't know that q Therefore S doesn't know that q This is an example of what's called an 'argument from ignorance'. It's often associated with the sceptical arguments Descartes put forward in his Meditations, and many philosophers take it to be a definitive statement of the sceptic's challenge to our perceptual knowledge claims. If we can't come up with a philosophical response to the argument from ignorance, the thought goes, the sceptic has exposed the fact that despite our intuitions to the contrary we cannot show how knowledge of the external world is possible.2 No-stipulations principle

A great deal of philosophical effort has been expended in the attempt to show that the argument from ignorance is unsound or otherwise uncompelling, and we will consider a number of specific attempts in subsequent chapters. For present purposes it's important to remember that the epistemological task is to show how knowledge is possible. As such, efforts to reject the argument from ignorance frequently focus on offering an analysis of knowledge that links its possibility to an account of where the argument from ignorance goes wrong. To take a simple example, let's imagine that knowing just requires believing that something is possible; that is to say, (A) S knows that q iff (if and only if) S believes it is possible that q On this account, the argument from ignorance is immediately shown to be unsound, as the first premise is false -1 do know that

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I'm not for example an envatted brain because I believe it's possible that I'm not. On this analysis the argument from ignorance does not therefore present an obstacle to the possibility of knowledge. The problem with this is that no one thinks that (A) is satisfactory - it fails to capture our intuitive sense of what it is to know something. The moral of this is the 'no-stipulations principle': the epistemologist can't just invent an account of what knowledge is in order to refute the sceptic and show that knowledge is possible. Now consider the following: (B) S knows that q iff everyone everywhere believes that g, but only on Wednesdays if it's raining What this suggests is that the no-stipulations principle also cuts the other way: an arbitrary account of knowledge that simply made it unobtainable would cause us to lose no sleep over our cognitive shortcomings. 'If that's knowledge,' we might exclaim, 'who gives two hoots that we don't know anything?' In short, at one extreme stipulation leaves sceptical doubt unintelligible at the cost of making knowledge worthless (A); at the other extreme it makes scepticism unthreatening at the cost of making knowledge impossible (B). We can draw two related conclusions from this. First, since no one stipulation as to what constitutes knowledge has any greater claim on us than any other, another guide is clearly needed. The knowledge whose possibility the sceptic doubts must be something of which we have an intuitive (perhaps pre-theoretical) grasp. It must be something connected to the way we (at least implicitly) use the concept in everyday life and which captures its importance to our understanding of ourselves as cognitively responsible agents (as creatures who value the distinction between knowledge and opinion). The second point takes us back to (B). The claim was that if this is what knowledge is, we don't care if it's not possible - the sceptic's doubt holds no fear for us. What this suggests is the possibility that it is not knowledge as such that we value, and which the sceptic threatens, but a more fundamental feature of our epistemic practices, one that the analysis in (B) fails to capture. Taken together, these point in an obvious direction: we must undertake a closer examination of what knowledge is in order to find out what it is about the sceptic's challenge that threatens our self-understanding;

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and in doing so we must allow our intuitions about when we do or do not know something to be our guide. Varieties of knowledge

Before looking in detail at the concept of knowledge we need to simplify matters. In formulating the argument from ignorance above I indicated that q was to stand for any empirical proposition. The knowledge the epistemologist is generally concerned with is prepositional knowledge. A proposition is what is expressed in a that clause. So, for example, my believing that there's a chocolate bar over there, my hoping that there's a chocolate bar over there and my fearing that . . . (etc.) express different attitudes (belief, desire, fear) to the same proposition; namely, 'there's a chocolate bar over there'. The content of the proposition is what makes it the proposition it is - in effect what it 'says'. Propositional knowledge is thus knowledge that such and such is the case, where the 'such and such' specifies the content of a particular proposition. There are of course other kinds of knowledge. One can know Paris or Tim, in the sense that one is acquainted with them or that they are familiar. More importantly, there are the diverse practical abilities sometimes described as varieties of 'know-how': Rachel knows how to drive, Tim knows how to ride a bike, Jonathan knows how to play the bass guitar. In traditional epistemology these varieties of knowledge are viewed as of secondary importance. After all, when we think of a human being, it seems that although no amount of 'knowledge that' (of facts) would provide them with the powers of coordination and balance required to ride a bicycle, they couldn't (know how to) do so if they didn't know that they had to push down on the pedals to go uphill. The issue is not clear-cut, however. Consider the case of a trained chimpanzee riding a bicycle round the circus ring. Would we say that it knows how to ride a bicycle; and if so, would we claim it's because it knows that it has to press down on the pedals? On the one hand, some rejectionist ('naturalistic') epistemologists think that an account of knowledge that denies it to animals is simply wrongheaded, but it seems evident that any such account will threaten to undermine the distinction between prepositional knowledge and knowledge-as-ability. On the other hand, indicating that a person

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knows how to ride a bicycle may suggest much more than the mere ability to propel him- or herself along. It might imply that they see bicycling as a way of getting themselves efficiently from one place to another, a mode of transport vulnerable to the eccentricities of pedestrians and the thoughtlessness of drivers, but nevertheless a healthy and therefore desirable activity in itself. If these sorts of factors are involved in ascribing such know-how to persons, then there is a strong sense in which chimpanzees, despite the complexity of their behaviour, don't know how to ride a bicycle. This undermines the distinction between knowing that and knowing how in quite a different way from the naturalist. We'll see more of the refectionist position below, and that alternative account of the relationship between knowing how and knowing that will re-emerge in Chapter 2. Noting that our intuitions, although our guide, are not always entirely clear, we will restrict out attention to prepositional knowledge, and review some contemporary thinking on the question of what knowledge is. This will advance our understanding of what it is that the sceptic's doubt really threatens. The analysis of knowledge

The most familiar approach to the analysis of knowledge is in terms of truth-conditions: (K)

S knows that q iff (Ca & C2 & C3 & C 4 . . . Cn)

Cp C2, . . ., Cn are the separately necessary and jointly sufficient conditions for the application of the concept. If the analysis is correct, then if it's true that S knows that q, C15 C 2 ,. .., Cn are all true (and if it's false that S knows that q, one or more of C1? C 2 ,..., Cn will be false). Whether or not such an analysis is possible, the attempt at one can provide some valuable insights, not least because of the associated method of using imagined examples of knowing to test the analysis against our intuitive grasp of the concept of knowledge.3 At the outset it is clear that in order to know that q, S has to believe that q. So we have our first necessary condition: (Cj)

S believes that q

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Belief itself is not enough: although one cannot imagine a case of knowing that isn't a case of believing, one can imagine a case of believing that is not one of knowing. What else is needed? One approach has been to regard certain belief as knowledge. As it stands, what one means by certainty is in need of further clarification. If one thinks of it in subjective terms, as a sort of feeling that one cannot possibly be wrong, the criterion is far too dependent on psychological considerations to provide an insight into knowledge. Viewed in objective terms, however, we begin to move in the right direction. To say that a belief is objectively certain seems to suggest that it is impossible to conceive of its being false. Thus understood, objective certainty would be a property of few of our beliefs: right now I believe that I'm sitting in the library, but I can imagine that the belief might be false; it's just that it isn't. What the talk of objectivity captures is that although any one of your beliefs might be false, in order to qualify as knowledge it must be true. So, (C2) q is true We thus have two necessary conditions for knowledge; the question is, are they jointly sufficient? Can one think of an example where one would say of Rachel both that she believes that q and that q is true, but that she doesn't know that g? The answer, in short, is 'yes'. Imagine that it suddenly 'pops' into Rachel's head that the bus she's due to take to Boston on Wednesday won't show up (a belief that g); or that she infers the same from having read in her horoscope that travelling on Wednesday is to be avoided. As it turns out, the bus doesn't show up: Rachel's belief (that q) was true; but would we want to say that she knew the bus wasn't going to show? Every textbook on epistemology has examples like this, but it's worth dwelling on why, although easy to construct, they seem odd. When we ascribe beliefs to people (and that, after all, is what we're doing to Rachel here), we usually do so on the assumption that the way they acquired their belief is linked up in some way with what it's about. In the example we have a kind of link: superstition or premonition or what have you, but it doesn't seem 'adequate'. Imagine a conversation with Rachel in which she tries to explain to us why she believes what she does about the bus; or our response when, having failed, she claims in desperation that she just knows it won't turn up!

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The problem with the 'true belief analysis is that from our perspective, and despite Rachel's protestations, it appears to be a matter of luck that her belief is true - a fortuitous accident. Moreover, we'd be inclined to think that she was an odd fish indeed for believing whatever pops into her head. It's not the sort of thing that the cognitively responsible person - one who values the distinction between knowledge and opinion - does. In short, the relationship of her belief to whatever it is that it is true of doesn't seem adequate: Belief (Subjective)

Adequacy

Truth (Objective)

The third term of the traditional analysis of the concept of knowledge seeks to address the issue of adequacy (rule out luck and accident) by elucidating a link between the subjective state and its objective truthconditions. To indicate that a belief is subjective in this context means only that it is a state of a subject S (the putative 'knower'). Similarly, the objectivity of truth means no more than that it is independent of the subject S: her belief that q does not imply that q is true. For much of this century, adequacy has been understood in terms of justification, thus providing us with a third term: (C3)

S is justified in believing that q

With (C3) we arrive at the so-called 'justified true belief (JTB) analysis of knowledge: (JTB) S knows that q iff (S believes that q) & (q is true) & (S is justified in believing that q)

Scepticism, justification and truth

Adopting to the justified true belief analysis, when a sceptic doubts the possibility of knowledge they are doubting one of the following: • The sceptic doubts that we have any beliefs • The sceptic doubts that any of our beliefs are true • The sceptic doubts that any of our beliefs are justified

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On the face of it, it might seem that we can immediately rule out the first possibility as self-refuting: how can anyone doubt that we have beliefs without having beliefs themselves? The case is not quite as simple as it appears, however, but we will put it aside until Chapter 2. Concerning the remaining two options, many (perhaps most) philosophers would argue that our interest in justification is its 'truthconduciveness', or 'truth-indicativeness': it's truth that we're really interested in, and we think justified beliefs are more likely to be true than unjustified beliefs (more likely in the sense of not being accidentally or fortuitously true). Returning to the example above, what Rachel lacked was a justification for her belief - something that linked her belief that the bus wasn't going to show with the bus not showing. One justification might have been that she knew that there was going to be a strike that day. This would entitle her to her knowledge-claim in the eyes of an audience (including herself) because the reason given links her belief to the conditions of its truth. It would therefore seem that it is the truth of our beliefs that is most vulnerable to the sceptic's doubt; but here are two reasons for thinking that this not straightforwardly the case. First, consider how a sceptic would inculcate such doubts. She is, after all, a philosophical opponent, who aims to undermine our confidence in the possibility of knowledge by providing reasons for doubt. If the sceptic simply said 'all your beliefs might be false', we would not take it as a serious threat to our epistemic confidence because we are being presented with no reasons to believe this the case. We'd simply shrug it off. The point is that just as we have no direct access to truth, but rely on the truth-conduciveness of justification to get us to it, the sceptic can only get us to doubt the truth of our beliefs by getting us to doubt that our ways of justifying them are adequate. Since we are interested in justification because of its truthconduciveness, to cast doubt on our methods or practices of justification - our ways of getting at truth - undermines our confidence that they can even be regarded as practices of justification. As we saw with the argument from ignorance, the sceptical possibilities lead us to consider that what we normally take to justify our perceptual beliefs - experience - isn't the guide to truth we take it to be, and is therefore no source of justification at all. There's one reason for thinking that the justification condition is the sceptic's target. Here's another: it's plausible to think that most

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scientific beliefs held up to the nineteenth century were false, and so didn't amount to knowledge (on the justified true belief analysis). Acknowledging the link between justification and truth, we might conclude that everything that anyone has ever believed that is false is therefore by definition unjustified. The problem with this is that we would be unable to make the crucial epistemic distinction between the (false) beliefs that we consider scientists had very good reasons to believe and the (false) beliefs held as a result of sloppy thinking or a belief in the supernatural (believing whatever 'popped' into their heads or what an angel purportedly revealed to them). Again, it's possible - perhaps even probable - that most of what the scientists of our own time believe will turn out to be false, but we still regard some epistemic practices as more reasonable than others. The fact that justification is truth-conducive does not mean that the best available practices of justification guarantee access to the truth, but they do make it more likely that we'll get at it. What is important is that the epistemic distinction between justified and unjustified beliefs is upheld, and it is this distinction that the sceptic attacks. What the justified true belief analysis suggests is that when the sceptic doubts the possibility of knowledge it is by raising doubts about the justification condition. The argument from ignorance demonstrates one way this can be done. By showing that what we take to justify a certain class of beliefs (perceptual beliefs etc.) is compatible with their falsity, the argument directly undermines the claim that such justifications are truth-conducive (and thus don't count as justifications at all). In the light of our analysis we could therefore rewrite it as follows: S isn't justified in believing that not-s/? If S isn't justified in believing that not-sp, then S isn't justified in believing that q Therefore S isn't justified in believing that q For completeness we'll call this the argument from ignorance (/'), although it will not figure much in what follows for reasons that

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will now become apparent; namely, because there is a more radical way of raising doubts about the justification condition - one that aims to undermine our confidence that there is any sort of reasoned distinction to be made between justified and unjustified beliefs. This relates to another basic form of sceptical argument that I'll call the 'Agrippan argument'. The Agrippan argument Although the Agrippan argument4 is perhaps the most ancient of sceptical arguments, it has undergone a distinct revival in recent years. Since Chapter 2 will deal with Ancient Scepticism in detail, we will begin by restricting our account of the problem to how a modern epistemologist would view it. To see how it arises, consider the following. In the course of conversation, S claims that q. Given the acknowledged and crucial epistemological distinction between knowing (or being justified in believing) that q and merely assuming (or being of the opinion) that q, it seems reasonable to ask S what justifies her in thinking that hers is a case of one rather than the other. Suppose that S now offers some evidence rl for her original claim; given the same acknowledged distinction it seems reasonable to ask if rl is itself something that she knows or whether she is merely assuming its truth. If this elicits a further source of evidence, r2, the same question can be repeated (for the same reason). In this way the demand for justification gets passed down along a line of justifying reasons (q —> r1 -» r2 —> r3 —> r4 —» r5 —> r6 - » . . . ) that threatens to regress endlessly. In response, S seems to have to choose one of the following options: (a) Continue to give reasons indefinitely, opening up the possibility of an infinite regress (b) Make a dogmatic assumption (c) Argue in a circle The problem with (a) to (c) is that each of them threatens to leave the original claim q unjustified in so far as they fail to ground (offer an ultimate or unquestionable source of evidence for) the distinction between knowledge and assumption/opinion. Consider (a): if the giving of reasons or the offering of evidence continues to infinity,

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there's no point at which one can say that the distinction between assumption and knowledge has been genuinely grounded. It is not the case that for example six iterations yield knowledge as opposed to assumption, because the entire weight of the distinction rests on the final source of evidence (in this case r6), and that stands unjustified. Similarly, with regard to (b), if S refuses or finds herself unable to give further reasons for her belief, that does not support the distinction. Indeed, it shows that it cannot be made; that since all claims ultimately rest on assumptions, all are equally unjustified. Finally, if S seeks to justify her claim by offering as grounds some reason or other sort of evidence she's already employed, she is implying that certain claims are self-supporting. Let's say r6 is the same as r^\ if rs is offered in support of r4 and r6 in support of r5, r6 carries the full weight of the justification, and yet it is the same as r3 (previously considered in need of support by r4). Since arguing in a circle - or 'begging the question' - is a classic way of demonstrating that someone is reasoning poorly, (c) is not a good basis for sustaining the vital distinction between being justified and merely assuming. One reaction to this argument is to suggest that there is something contrived about it; and it is indeed reminiscent of the child who responds to every answer with the question 'but why?' Of course, adults tend to end such 'debates' with an exasperated 'because I say so!' or 'that's the way it is!'; and no one doubts that such dialogues with others or oneself (I can ask myself if I know that g, and generate the same problem) do come to an end. The problem is that if, when we reflect on it, it is reasonable to ask the original question 'Do I know/am I justified in believing q or am I just assuming that g?', terminating the enquiry through boredom or failure of imagination or with what we imagine would be accepted by anyone is entirely arbitrary. The significance of this is obvious. As we saw above, we are interested in justification because of its truth-conduciveness, and beliefs resting on arbitrary assumptions can give us no confidence that they are justified and thus more likely than not to be true, even if they are accepted as common sense. Since the Agrippan argument confronts us with the apparent impossibility of making sense of the vital distinction between justified and unjustified belief, it undermines the idea that any of our beliefs are so much as justified at all. To put this another way, where the argument from ignorance suggests that our empirical beliefs are not in any way constrained by or

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answerable to the external world (because we can with equal validity consider ourselves awake, asleep or an envatted brain), the Agrippan argument suggests that none of our beliefs - none of our thinking in general - is in any way answerable to (adequate to) anything other than itself! Not surprisingly, philosophers who have recognized the force of the Agrippan argument have been anxious to avoid the sceptical consequences of (a), the threat of an infinite regress. To summarize, this has expressed itself through attempts to show that (b) and (c) do not have the seemingly disastrous consequences the sceptic suggests. On the one hand, the 'foundationalist' denies that all assumptions are dogmatic: (Fo) There are some beliefs that do not stand in need of further justification, and which serve as the grounds for other claims. On the other hand, the 'coherentist' denies that beliefs are justified in a 'linear' manner, and therefore that circularity need be vicious: (Co) Beliefs are linked together in a complex system and lend one another mutual evidential support. If either of these options could be fully realized it would seem that the heroic epistemologist could claim to have shown that the Agrippan argument presents no challenge to the task of showing that knowledge is possible. It is not immediately clear what implications this has for the argument from ignorance, but if the justified true belief analysis is correct, the heroic epistemologist might be confident that his account of knowledge will also show where the argument from ignorance goes wrong. If that seems to limit the epistemological options, however, consider the following objections: 1. The presentation of the Agrippan argument presupposes a very specific conception of justification - one that ties it to S's having access to (knowing) whatever it is that might justify her claim that q (and hence rp r2, etc.). If we reject that account of justification we could avoid the regress, leaving the being justified/assuming distinction in place.

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2. Whatever the Agrippan argument shows, it does not undermine the distinction between knowing and assuming because it is a mistake to suppose that justification is even needed for knowledge. Anyone familiar with recent developments in epistemology will recognize these: they are expressions of what I have called rejectionism and they clearly bear on our investigation. If the sceptic is presupposing something unwarranted about the nature of justification (1), we might well have grounds for dismissing the Agrippan argument (and perhaps the argument from ignorance (/)). Alternatively, if the sceptic is presupposing something unwarranted about the necessity of justification (2), the Agrippan argument and the argument from ignorance (/') are misconceived since their target has no bearing on our possession of knowledge. The expectation would be that the analyses put forward as part of (1) and/or (2) would also provide a response to the traditional argument from ignorance. Since I've suggested that the Agrippan argument is the more radical form of scepticism, the remaining task for this chapter is to begin the enquiry into whether or not (1) and (2) do allow us to reject it. Before doing so we'll review the recent changes in epistemology mentioned above. This will support my claim that rejectionism can be regarded as a reaction to the perceived failure of heroic epistemology. It will also allow for the introduction of some jargon that is common currency among epistemologists today. Gettier In 1963 a very short paper by Edmund Gettier generated a great deal of interest and has had an enormous influence on subsequent developments in epistemology. The purpose of "Is Justified True Belief Knowledge?" is evident from the title; namely, to question the adequacy of the traditional analysis of knowledge. In his paper Gettier offers two counterexamples to that analysis - situations where our intuitive understanding of knowledge fails to map on to what the justified true belief analysis suggests it ought to. Although Gettier had no interest in scepticism, what have become known generically as 'Gettier examples' have led to major revisions in the analysis of knowledge and, as a consequence, in the

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understanding of the significance of scepticism. Consider the following situations: Example 1 Act I 5

Smith and Jones have just been interviewed for the same job. Smith's friend works in the personnel department and informs her that he's just overheard his boss state that Jones is to be offered the job. Smith's passion for numismatics has led her to discover that Jones has 1 0 coins in her pocket, so she has strong evidence for the following conjunction: (I) Jones will get the job and Jones has 10 coins in her pocket. This entails: (II) The person who will get the job has 10 coins in their pocket. Since Smith has strong evidence for (I), and recognizes that (I) implies (II), she has strong evidence for believing (II) is true.

Act 2

Unbeknown to Smith, it turns out that she and not Jones will get the job after all (maybe the head of personnel got the names confused). It then transpires that Smith herself has 10 coins in her pocket. That being the case, it turns out that Smith's belief (II) is true, but would we want to say that she knew that was true? After all, that belief was based on her belief that Jones and not herself had 1 0 coins in her pocket

Philosophers anxious to save the traditional analysis were quick to offer a response to this by supplementing the justified true belief conditions. Noting that Smith bases her true belief on a falsity, one might try the following: (C4) S's belief that q is not inferred from any falsehood Unfortunately, others were quick to come up with arguments in the style of Gettier that didn't allow for this quick escape:

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Example 2

Act 1 6

Out (soberly) celebrating her new job, Smith drives along a country road and, spotting a barn in the middle distance and having good eyesight, acquires the justified belief that it is a barn.

Act 2

Unbeknown to Smith, however, she has been driving through barn-fagade country, an unusual stretch of road that annually attracts the attention of neo-realist artists competing for the prize of most convincing fagade ('As Seen From The Road' section). Had any of the previous or subsequent objects caught her attention she would have equally justifiably judged them to be barns, and would have acquired a false belief. It just so happens that her attention is drawn to the one genuine barn in the area (used by the judges as the standard, perhaps) and her belief is true. But would we want to say that she knew that she saw a barn?

In this example, there is no inference from a false belief to a true belief (so C4 is satisfied); indeed, it's reasonable to assume that there is no inference at all - she just sees a barn. Moreover, it would seem that Smith's belief is about as justified as one could hope for. And yet we would not attribute knowledge to her. Why not? Well, as in Example 1, it seems that the connection between her belief and its truth-conditions isn't adequate - it was a matter of epistemic luck that she happened to form a belief about the one real barn in the area. What Gettier examples seem to show is that even if necessary, justification is not sufficient to satisfy the demands of adequacy. Internalism and externalism

How then have epistemologists responded to the situation, and what implications do their responses have for scepticism? Let's return to the justification condition: what exactly does it mean for a belief to be justified? One response - that of the 'evidentialist' - is to argue that one must have adequate evidence for it. This evidence usually comes in the form of other beliefs that S must be aware of as supporting her belief. In this sense, evidentialism is closely associated with two further doctrines: 'internalism', and the so-called

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'KK principle' (or 'KK thesis'; also known as the 'iteration principle'). Internalism, and its contrasting term 'externalism', are used widely in epistemology and not always with clarity. Robert Fogelin (1994: 120) usefully disambiguates two varieties of internalism about justification: • Ontological internalism: for S to be justified in believing that g, the grounds that justify this belief must be contents of S's mind. • Methodological internalism: for S to be justified in believing that g, S must base her belief on the grounds that justify it. What methodological internalism indicates is that in order for S to be justified in her belief that g, the evidence that would normally justify it (the 'grounds' for believing that q) is the evidence that S actually uses to arrive at q. If what justifies Smith believing that there's a barn outside (normally) involves seeing the back as well as the front, and that is the grounds upon which she bases her belief (she gets out of the car to check), then from the perspective of the methodological internalist her belief is justified. To this the ontological internalist adds a restriction on what kind of evidence can justify beliefs. To many philosophers it has seemed natural to suppose that the only source of evidence apt to provide grounds for knowledge claims is the contents of one's own mind, because these are things to which we have a privileged and immediate access (my beliefs and experiences are mine; I don't infer what's going on my own mind - I just knowl). Ontological internalism is thus closely associated with a further variety of internalism: • Semantic internalism: the 'content' of S's belief that q - what makes it the belief it is - is entirely determined by what is going on inside S's mind. We'll discover more about the connections between these varieties of internalism in Chapter 3 when we look at Descartes. What is clear is that both Ontological and methodological internalism are evidentialist - they agree that for S to be justified in believing that q, S must recognize what it is that justifies her belief that q\ they just disagree about what the acceptable sources of evidence are.

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It is this shared commitment that links evidentialism to the KK-principle: (KK) If S knows that q then S knows that she knows that q If knowing that q requires having adequate grounds in the form of evidence that one recognizes as evidence, it follows that if you know, you know that you know (you know that the evidence is what justifies the belief, and thus that you know). Given these definitions, the externalist - anti-evidentialist alternatives fall into place. Minimally, an externalist denies that S's grounds need be contents of her mind. Most externalists will also deny that S need base her belief on the grounds that justify it, and therefore deny that she need be aware of those grounds. More radically, many externalists go so far as to deny that justification is even necessary for knowledge. The rejection of the KK-principle is therefore the hallmark of most varieties of externalism. Finally, the semantic externalist maintains that the 'content' of S's belief that q is at least partially7 determined by how things are in the world external to her own mind. Henceforward I'll use 'internalism' to refer to the methodological thesis, and 'externalism' to refer to any position that rejects it. Returning to the Gettier examples, we have seen that these appear to undermine the traditional analysis of knowledge by drawing attention to the apparent inadequacy of the justification condition. We are now in a position to see how, in broad terms, contemporary epistemologists have responded to the challenge: The internalist options

(Inl) Take justification to be internalist (evidentialist) and offer an account that is adequate (immune to Gettier examples). (In2) Take justification to be internalist (evidentialist) but supplement it with an external condition (a 'fourth clause'). The externalist options

(Exl) Take justification to be externalist (non-evidentialist) and offer an account that is adequate.

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(Ex2) Remain agnostic on the question of whether justification is internalist or externalist but reject the claim that justification is needed for knowledge at all. Heroism, rejectionism and scepticism

With the above classification in place we are in a position to make good on some earlier undertakings: to address whether or not the two rejectionist objections (1) and (2) above allow the epistemologist to avoid the Agrippan argument; and to investigate in more detail the relationship between the heroic, rejectionist and sceptical responses to the task of epistemology as characterized by Stroud. Seeing how these two considerations are related will give us an appreciation of the need for a historical enquiry into the nature of sceptical doubt. First, it should now be evident that the epistemological theories most immediately threatened by the Agrippan argument are what we would now recognize as being internalist-evidentialist. There are important differences between the traditional approach (Inl) and what are sometimes called 'Indefeasibility Theories' (In2),8 but for our purposes these share the assumption that in order for S to be justified in believing that q, she must be aware that her evidence has the justificatory force it does. Indeed, the KK-principle to which internalists share a commitment is an explicit statement of this. Such internalists are clearly obliged to offer a response to the Agrippan argument, and given the options, those responses will fall into one of two classes: they will be either coherentist or foundationalist. Since the heroic epistemologist recognizes the need to demonstrate that knowledge is possible by refuting the sceptic, heroic epistemology will therefore be either coherentist or foundationalist. Let's now turn to those two rejectionist objections. The first (1) was to the effect that the Agrippan argument presupposes a certain conception of justification, which we can now identify as internalist in character; the second (2) dismisses the argument on the grounds that justification is not necessary for knowledge. The proponent of (1) will incline towards the first externalist option (Exl) and aim to elaborate an account of justification that does not succumb to the Agrippan argument; the proponent of (2) will favour the second externalist option (Ex2) and offer an account of knowledge that does not involve justification at all.

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Lining up internalist and externalist options in this way gives us an insight into the relationship between heroism and rejectionism. Heroic epistemology confronts two major problems. On the one hand, demonstrating that knowledge is possible requires a response to the Agrippan argument; on the other, the justified true belief analysis of knowledge that heroic epistemology has come to rely on seems to offer an unsatisfactory account of what knowledge is (in the face of Gettier examples). Since a commitment to internalism seems to underpin both these problems, the rejectionisfs key intuition becomes clear; namely, that rejecting the heroic demand for a legitimating account of knowledge involves the theoretical formulation of an externalist alternative that avoids heroism's two problems. It should be noted in passing that even if the rejectionist were successful in avoiding these two problems, that would not by itself constitute a solution to our first sceptical problem, the argument from ignorance. Externalist-rejectionist responses to this argument will be one of the main topics of Chapter 6, but for now we need to determine whether or not (Exl) and (Ex2) really promise the possibility of an analysis of justification or knowledge that restricts the scope of the Agrippan argument to heroic, internalist-evidentialist epistemologies. This will in turn lead to an appreciation of that third, sceptical response. I'm going to suggest (Exl) and (Exl) do not avoid the Agrippan argument by considering two arguments: the first shows that externalism fails to restrict the scope of the argument; the second explicitly broadens its scope to include externalist theories of justification and knowledge. The first argument takes us back to the no-stipulations principle. Whatever account of knowledge or justification the epistemologist advances must be one that captures why we value knowledge over opinion or assumption - the feature or features that touch upon our cognitive self-understanding. As we saw with the know how/know that distinction, intuitions are not always clear, but they led us to consider the necessity for justification in the first place. Gettier examples may show us that justification is not enough, but they don't as they stand show us that justification isn't important, which is why the two internalist-evidentialist options (Inl) and (In2) remain philosophically alive. The fact that an account of justification or knowledge avoids the Agrippan argument is not in itself enough to recommend it to us.

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With this in mind, consider a variation on an example used above.9 It turns out that since we left her, Rachel has become a clairvoyant with entirely reliable powers of prognostication. Rachel has no idea that she has this power and indeed is extremely sceptical about the existence of such a power generally. Now imagine that it suddenly 'pops' into Rachel's head that the bus she's due to take to Chicago on Thursday won't show up. According to externalists, the fact that Rachel has the power she does means that her belief is in fact justified (Exl) or is in fact a case of knowing (Ex2), whatever she herself thinks about it. In such circumstances, would we want to say that Rachel is justified in believing that q or that she knows that g? Or to put the same point slightly more archly, if in these circumstances Rachel did claim to know, would we consider her claim to be a genuine case of knowing? If this talk of supernatural powers confuses matters, imagine instead that an Amazonian-forest-dwelling and hitherto unassimilated Rachel stumbles upon a telescope. She doesn't know anything about optics or astronomy and absolutely believes that the lights in the sky are the souls of her dead ancestors. Nevertheless, when she observes a planet she decides that it is a solid body and not a twinkling soul. Would we say she knows this? The point of the examples is that they present cases where the would-be knower is in some sense irrational in coming to the conclusion that they do - that is to say, they only have the belief they do because from their own standpoint (internally) they are willing to live with crazy inconsistencies. From our perspective, this undermines an important feature of whatever the context for knowing is; namely, that a belief has to be reasonable from the knower's own point of view, and not just be objectively reliable. This suggests that justification and knowledge have an irreducibly internalist element. These examples are mirror images of the Gettier examples: where the latter exploit the weaknesses of internalist theories by pointing to cases of epistemic luck, these exploit the weaknesses of externalist theories by pointing to cases of cognitive irresponsibility. It's worth noting that contemporary epistemologists have gone into less detail than they might have when considering the implications of these cases of cognitive irresponsibility. For example, if (say Clairvoyant) Rachel did indeed maintain that she knew about the bus and we judged her irrational, would we consider her failure in

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this instance to infect other claims that she makes? Might we contemplate the possibility that she doesn't really know anything at all? As we'll see in Chapter 1, this sort of question resonates with the concerns of ancient Greek philosophers. For present purposes, the conclusion of our first argument is that if rejectionist analyses of knowledge and justification do not allow for an internalist element (as neither (Exl) nor (Exl) do), they cannot satisfy our intuitions about knowledge and therefore cannot restrict the scope of the Agrippan argument in any sense that makes such a restriction valuable to us as responsibly minded knowers. Let's now turn to the second argument I mentioned - the one that widens the scope of the Agrippan argument. Imagine that Tim is an externalist of either variety ((Exl) or (Ex2)). He advances the claim that S justifiably believes or knows that q because S satisfies the appropriate external standard of justification or knowledge (ES), whatever that is. But now imagine his interlocutor Lois. She has two options. She can ask Tim if he knows that S satisfies the standard or if he is just assuming that it does. If he says he knows, Lois might go on to ask him what his evidence is and off we go again. This response is most immediately problematic for the proponent of (Exl), as he believes that something justifies S's belief, and it seems natural to ask how that something could be a justification unless someone were aware of the fact. All (Exl) seems to do is shift the awareness of justification from one person (S) to another (Tim), so the Agrippan argument adjusts its target accordingly. It would appear that the second variety of externalism (Exl) can't easily escape this one either. S's knowing might not require that she knows that she knows, but it does seem to require someone knowing that she knows, and that can only be Tim. Here the awareness of knowing seems to be shifted from S to Tim. Now consider Lois's second question. Here she asks, not if Tim knows or assumes that ES (the external condition for justification or knowledge) has been satisfied, but if Tim knows or is only assuming that ES is the appropriate external standard. In other words, Lois addresses herself to Tim's claim to have in his possession a piece of philosophical knowledge. Again, if Tim says he knows, Lois will ask for his evidence and off we go again! Here, we encounter the Agrippan argument with its widest scope, where it leads to pfe-scepticism - scepticism about the possibility of philosophical

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knowledge and therefore about the possibility of offering any justification of our concept of knowledge. Finally, then, we return to the third response to the epistemological task - what I called the sceptical response. Importantly, from the perspective of this response the /?£ro/c-internalist attempt to legitimate knowledge and the externalist-rejectionist attempt to offer an account of knowledge or justification that avoids the problems this generates are on a par. They both presuppose that there is such a thing as philosophical knowledge and that it is therefore possible in principle to accomplish one of these tasks. As already noted, the variety of scepticism that rejects the possibility of philosophical knowledge is the oldest form of scepticism (what I called p£-scepticism). Part of its legacy is the Agrippan argument, which remains the most radical challenge to our self-understanding as knowers even when contemporary epistemologists restrict its scope to empirical justification. More importantly, it also provides the resources for the best response to the contemporary epistemologist's sceptical problems. The last claim will doubtless strike the reader as being somewhat paradoxical - using scepticism to respond to scepticism! To see tha this is not the case we need to know more about how theoretical attitude doubt differs from Ancient Scepticism, and consequently what relation the latter has to the Agrippan argument and to the argument from ignorance (which many philosophers still take as the paradigmatic expression of modern scepticism). This will in turn prepare us for an appreciation of the extent to which themes from the Ancient tradition have recurred throughout the subsequent history of philosophy. In Chapter 2 we will begin to address these concerns by returning to scepticism's Hellenistic roots.

2

The legacy of Socrates

Introduction

Hitherto we have encountered scepticism as presenting epistemologists with a certain theoretical problem; namely, to show that our empirical beliefs are held on rational grounds by demonstrating that the distinction between being justified in believing that q and merely assuming that q is legitimate. Although the sceptic who uses philosophical arguments to generate doubt about our practices of justification was contrasted with the /?£-sceptic who challenges the possibility of philosophical knowledge, the latter too was seen as posing a theoretical obstacle, in the form of the radical version of the Agrippan argument with which we concluded Chapter 1. In both cases, then, scepticism was associated with theoretical attitude doubt. This theoretical picture of pfe-scepticism and the threat of the Agrippan argument differs from the one that emerges when one looks at the Ancient Sceptics. Like their traditional foes the Dogmatists, these were concerned with the role that philosophy has to play in determining how human beings should live their lives. Principally the Sceptic's view was that rather than guide us in the search for the knowledge that would enable us to live happy lives, philosophy should cure us of the disposition to believe that there is any such knowledge. Inspired by the legacy of that most enigmatic of figures, Socrates (c. 469-c. 399 BCE), they attempted to make sense of his seemingly paradoxical claim that the one thing he knew was that he knew nothing.1 In part, then, our task is to trace how the Sceptics dealt with this paradox, which leads to what I'll call the Essential Problem of Ancient Scepticism. Beyond this, an appreciation of the

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challenge of Ancient Scepticism will allow us to better understand the subsequent development of sceptical thought, and give us a sense of what the possibilities are for evaluating and responding to it today. The Essential Problem

Scepticism in the ancient world can be classified under three headings: the Practical Scepticism of Pyrrho (c. 360^;. 270 BCE) and his pupil Timon (c. 320-230 BCE); the Academic Scepticism of Arcesilaus (315-240 BCE), Carneades (c. 214-129 BCE), and his pupil Clitomachus (c. 187-c. 110 BCE); and the neo-Pyrrhonism of Aenesidimus (c. 100-40 BCE), Agrippa (c. 1st century CE), and Sextus Empiricus (c. 160-c. 210 CE). Although little is known of Sextus's life, and he is not regarded as having been an important thinker in his own right, much of what we know about Ancient Scepticism is derived from his surviving works. Of these, the Outlines of Scepticism2 has historically been the most influential, not least because it is the primary source of the Agrippan argument. In its opening sections Sextus describes the ways in which one might conceive of philosophical enquiry: When people are investigating any subject, the likely result is either a discovery, or a denial of discovery and a confession of inapprehensibility, or else a continuation of the investigation. This, no doubt, is why in the case of philosophical investigations, too, some have said that they have discovered the truth, some have asserted that it cannot be apprehended, and others are still investigating. (I. 1-2) These options designate the practitioners of "the most fundamental kinds of philosophy" (I. 4): • The Dogmatists: those who "think that they have discovered the truth" (I. 3). • The Academics (or Academic Sceptics): those who "have asserted that things cannot be apprehended" (ibid.). • The Sceptics (or neo-Pyrrhonian Sceptics): those "who are still investigating" (ibid.).

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For Sextus, the Dogmatist and the Academic present mirror images of each other: where one asserts that knowledge is possible (that things can be apprehended), the other denies it. To put this more precisely, the Dogmatist assumes that we can have the philosophical knowledge that shows that knowledge is possible. Equally, the Academic assumes that we can have the philosophical knowledge that shows that knowledge is not possible. If we take p-knowledge to be a particular kind of higher-order (philosophical) knowledge that justifies lower-order knowledge, this gives us: • The Dogmatists: we can p-know that knowledge is possible. • The Academics: we can p-know that knowledge is not possible. The neo-Pyrrhonian Sceptic aims to rise above this ancient antagonism by showing that neither position is rationally sustainable. He maintains that we cannot assume that we can have the philosophical knowledge that would show either that knowledge is possible, or that it is not possible. More specifically, the charge against the Academic is that to assert that to p-know that knowledge is not possible is to assume that p-knowing is 'insulated' from the attack that the Academic Sceptic himself wishes to launch against knowing simplidter. If it weren't, then to claim to know that one doesn't know would be contradictory (like asserting that 'there's no such thing as the truth, and that's the truth!'). By refusing to take a stand on the question of whether one can or cannot p-know, the neo-Pyrrhonian response in effect undermines the distinction between the two putative ways of knowing: • The Sceptics: we can't p-know that knowledge is possible, but neither can we p-know that knowledge is not possible. The extent to which it is possible to insulate p-knowing from knowing and thereby avoid the seeming paradox of asserting that nothing can be known leads us to what I referred to above as the Essential Problem. To understand this problem aright we need to know a little more about what the Greeks understood by knowledge; and in particular how they conceived of the role of philosophy. It will help if we think about the Ancients' views on philosophy in this period as exemplifying answers to three basic and related questions:

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• The 'constitutive' question: what are things like in their essential nature? • The 'hypothetical' question: what can or cannot we know? • The 'normative' question: how should we act and what will the outcome be? It is important to recall that central to Greek philosophy is the concern with living a good, virtuous or tranquil - that is to say, happy - life. The knowledge that the Dogmatist philosopher seeks is not therefore to be equated with the narrowly theoretical notion we encountered in Chapter 1. To know that q (that, for example, the world is round) may commit one rationally to other sorts of beliefs (like believing that there is a world), but taken alone it would not change one's practical orientation towards the world (what one does; how one acts). When discussing the relationship between prepositional knowledge and knowledge as an ability (know-how), I suggested that there were two ways in which the distinction might be undermined. One of them was motivated by the naturalistic desire to ascribe knowledge to animals; the other by the intuition that when the ability to ride a bicycle (for example) is ascribed to a person, that might suggest all manner of related interests (healthy living) and anxieties (safety) as well as knowledge of facts. The sort of knowledge that relates to living a 'good' life is like this - in addition to any strictly cognitive or theoretical element of 'knowing that', it involves the possession of component capacities and abilities.3 For the Dogmatist the guiding idea is that philosophical (p-)knowledge facilitates the living of a 'good' life. Through an account of the way things are in their essential nature, and what as a consequence we can know, we are led to an understanding of how we should live. So what does this tell us about the Sceptic and the Essential Problem? Crucially, Sceptics of all varieties (Practical, Academic, and neoPyrrhonian) share the Dogmatists' practical orientation. In attacking Dogmatism, then, the aim is not to undermine the conviction that there is an ideal sort of life for a human to live. Rather, the general project as conceived by the Ancient Sceptics is to use philosophy to attack the Dogmatic assumption that the good life is to be characterized and attained through the acquisition of knowledge. As a startingpoint we'll take it that the three questions above apply equally to the

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Sceptic in so far as he is using philosophy to attack philosophy. This will change as we get a better understanding of the extent to which Ancient Scepticism develops a different understanding of what philosophy is, but for the time being it gives us a clearer formulation of the Essential Problem. Accordingly, the Sceptic has to offer a response to the constitutive, hypothetical and normative questions that satisfies two conditions: (TC) It is not self-defeating. However the attack on knowledge proceeds, it cannot leave the Sceptic in the paradoxical position of denying something that their own account requires the assertion of. (PC) It retains its practical orientation. However the attack on knowledge proceeds, it cannot render unintelligible the idea that there is a way in which one should live one's life (and that this involves acting in the world). The Essential Problem is a problem for all Sceptics. In our brief exposure to Sextus's thought we saw that he is apt to convict the Academic Sceptic of failing to satisfy the 'theoretical condition' (TC) on the grounds that he assumes that one can justify the claim to p-know that knowledge is not possible; that is to say, there is something contradictory about his attempt to use philosophy to attack philosophy. By implication, Sextus would regard the neoPyrrhonian as satisfying both the theoretical condition and the 'practical condition' (PC). This evaluation of the relative merits of Academic and neo-Pyrrhonian Scepticism is prevalent to this day, which is part of the reason that Academic Scepticism has generally been neglected as a viable philosophical position. We'll be in a better position to judge whether or not the Academic has a satisfactory response to the Essential Problem by the end of this chapter, and, as a consequence, if this neglect is justified. Before examining the arguments of the Academics and the neo-Pyrrhonian Sextus, however, we'll look at their precursor Pyrrho. Beyond belief

Although he remains a somewhat shadowy figure, Pyrrho's influence was nevertheless considerable. The little that is known of his

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views serves as a good introduction to what motivates the Ancient Sceptic, and to the challenge that the Essential Problem presents. Acknowledging that an enquiry into our capacity for knowledge (understood in the broad sense) is critical if we are to arrive at an understanding of what a happy life would be and how to live it, Pyrrho is reported as arriving at the following position: Things are equally indifferent, unmeasurable and inarbitrable . . . neither our sensations nor our opinions tell us truths or falsehoods. Therefore for this reason we should not put our trust in them one bit, but we should be unopinionated, uncommitted and unwavering, saying concerning each individual thing that it no more is than is not, or it both is and is not, or it neither is nor is not. The outcome for those who actually adopt this attitude . . . will be first speechlessness, and then freedom from disturbance (ataraxia); and . . . pleasure. (Aristocles, IF. Italics added) With our taxonomy in mind, this gives us the following: • Answer to the constitutive question: The things that comprise the world lack any determinate characteristics. Everything in its very nature is incognitive. • Answer to the hypothetical question: Nothing at all can be known. • Answer to the normative question: We should not hold opinions, but suspend judgement about everything (epoche). The outcome will be a life of tranquillity (ataraxia). As this stands, it is clear that Pyrrho's view possesses the defining feature of Academic Scepticism as Sextus understands it. Where the Dogmatist contends that knowledge constitutes the very possibility of achieving happiness, Pyrrho maintains that what we p-know about the nature of things warrants scepticism about such knowledge. As Aristocles points out, this scepticism about the possibility of knowledge is inferred from the assertion about the nature of things. As a result of that inference, the wise recognize that neither the senses nor anyone's opinions are in any way indicators or standards (criteria) of truth, and therefore come to see that they should

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avoid the mental discomfort that issues from using them to decide what is and is not true. They conclude that living a life in which they do not hold opinions but suspend judgement and remain in a state of equipoise will satisfy the traditional desire for happiness. From a contemporary perspective this confronts us with a problem. In Chapter 1 we identified three possible targets for the modern sceptic's doubt: truth, justification and beliefs themselves. At that time it seemed absurd to regard the sceptic as doubting that we have beliefs; after all, such doubt would naturally be thought of as a belief! Since 'holding opinions' sounds like having beliefs, it appears that Pyrrho is not only rejecting the claim that our beliefs have a normative character (since everything is 'incognitive'), but is advocating living a life without any beliefs. It is not surprising that for many years Pyrrho's views were summarily dismissed as viciously self-refuting. Although this interpretation is misleading, it is instructive, because the rejection of opinion is common to all varieties of scepticism. To defend Pyrrho on this point therefore removes one obvious objection to Ancient Scepticism in general. Given the two conditions that any solution to the Essential Problem must satisfy, the situation appears to be as follows. With respect to the practical condition, any understanding of what it is to 'live a life' suggests people making judgements about how they should act, and yet Pyrrho's answer to the normative question stipulates that we should not make judgements (have opinions) about anything. With respect to the theoretical condition, the argument that we don't know anything (the answer to the hypothetical question), and therefore shouldn't make judgements about things, is advanced on the basis of an answer to the constitutive question; and yet the latter is a judgement (opinion) about the nature of things - a purported item of knowledge. In the first case it would seem that Pyrrho's view is contradicted by the practical unavoidability of having to have some sort criterion for action; in the second by the theoretical unavoidability of being rationally consistent. In order to bring these criticisms into focus, we need to relate Pyrrho's talk of 'opinions' to our own all-encompassing concept of belief. Consider the following: 1 People can no more live without beliefs than they can without oxygen. It is practically impossible for a person to function as a

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person - live a life of the morally significant sort - without beliefs. Beliefs are real. 2 Our commonsensical way of understanding the behaviour of people (ourselves and others) - what we call 'folk psychology' - is a theory. It is theoretically impossible to understand why people act as they do without ascribing beliefs (and desires) to them. Beliefs are theoretical items (like neutrinos and positrons). 3 Being a person entails being a believer. Beliefs are states of persons: it is conceptually impossible to even be a person without having beliefs. In the light of these possibilities, to advocate living a life without beliefs suggests one of the following: V An acceptance that beliefs are real, but rejection of the claim that they are guides to action. 2' An acceptance that beliefs are theoretical, but a rejection of the claim that they are needed to explain how people should and should not act in order to achieve happiness.4 3' An acceptance that beliefs are guides to action, but a denial that to be a person living a life of the desirable sort one need do anything at all. (!') and (2') presuppose that (3) is false, since one could only deny that beliefs themselves or the concept of belief are useful if one denied that to be a person one must have beliefs. In other words, the concept of belief must be such that we can detach our grasp of it from our understanding of what a person is; otherwise it would be like saying that it's useful for triangles to have three sides but that they'd still be triangles even if they didn't! (3') goes even further and detaches the concept of action from our understanding of what a person is. To make sense of Pyrrho's views in terms of contemporary belief-talk, then, he must be presupposing one of the following: (a) An understanding of persons such that one can make sense of their living a good life but not acting (from 3'). (b) An account of what beliefs are that warrants the conclusion that they are practically or theoretically useless (from V and 2').

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(c) An acceptance of the everyday sense of the concept of belief in which we use it to understand why people act in the way they do (from 3). First, there are no grounds for thinking that Pyrrho had any account of what beliefs are that would allow them to be seen as useless in the senses indicated in (b). Secondly, he did not consider that a life without opinions was a life of inaction: although the Sceptic purposefully withholds affirming that things are a particular way in their very nature, he can go along with appearances (phainomenon: objects as they are perceived) and these provide a criterion for action. Since that leaves only (c), the statement that one should live a life 'without opinion' must amount to something other than a rejection of belief as such. What Pyrrho seems to be advocating is that the wise should accept at face value ('go along with') a certain class of beliefs (the apparent), but refuse to assent to beliefs in the non-apparent ('opinions') of the sort that characterize Dogmatic views about the nature of reality. With respect to the practical condition, then, a life without belief is not unintelligible if it is understood as the rejection of a certain class of beliefs. The acceptable beliefs are not lacking a normative dimension and therefore can serve as criteria for action, but their normativity does not derive from any consideration of their ultimate truth. To see the significance of this, consider the advocate of the justified true belief analysis again. When he says that S believes that g, he indicates that S believes that q is true; and it is this link to truth that is held to give beliefs their explanatory power. Now consider Tracy, an ardent student of Pyrrho. She asks our justified true belief analyst to pass her coat and he ascribes to her the belief that (say) he has her coat - a belief that she must hold to be true if he is to understand her request (even if it is in fact false). If he now asks Tracy if she thinks that her belief is true, she will respond that it appears to her that he has her coat in his hand but as to the ultimate truth of the claim she would not like to say, since that would be to assert something about the nature of things (which are unknowable). From her perspective, what he describes as holding true, she describes as going along with appearances. As we've seen, for the modern epistemologist the important contrast is between holding true and knowing (or being justified in believing). For

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Pyrrho (and Tracy) the criterion of action derives from the contrast between going along with appearances and assenting to the nonapparent. On this interpretation Pyrrho's claim that we should avoid holding opinions does not violate the practical condition and leave us without a criterion of action; but what of the theoretical condition? The problem here is more exacting, because it does seem to be the case that the conclusion that nothing can be known is inferred from a judgement about the nature of things; and yet this sort of judgement is precisely what we are enjoined to avoid making on the grounds that we don't know anything. Pyrrho thus seems to be committed to the view that the p-knowing that concerns the nature of things is 'insulated' from the scepticism that it gives rise to. Indeed, this must be the case, because it is our p-knowledge that striving for knowledge is pointless that motivates the conclusion that happiness is to be found by avoiding the search and not by continuing it. Moreover, it is our p-knowledge that knowledge is impossible that underpins the distinction between the apparent and the non-apparent and thus furnishes Pyrrho with a criterion for action (the former). If it weren't for the insulation of p-knowing from scepticism, he would not be able to satisfy the demands of the practical condition. Unfortunately, this view invites attack from both the Dogmatist and the more thoroughgoing Sceptic. The Dogmatist can point out that since Pyrrho admits that we can p-know at least one ultimate truth, he has given them cause for renewed optimism because he has demonstrated that Dogmatism must be true - there is some philosophical knowledge that provides a guide to the good life and maybe we can come to p-know even more. The Sceptic can remind Pyrrho that leaving open this possibility for further philosophical enquiry is not the way to get us to avoid holding opinions and achieve happiness (ataraxia) and then go on to ask him on what basis he claims to p-know that his answer to the constitutive question is correct. Socratic method

From our discussion of Pyrrho we can draw the following conclusions that relate to Ancient Scepticism in general. First, the rejection of

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opinions is not contradictory if it is understood as the rejection of a certain class of beliefs. As a corollary to this, it is not senseless to suggest that human happiness depends upon the achievement of a state of tranquillity wherein the search for the truth about the real nature of things is abandoned. Rather than being the essential guide to happiness that the Dogmatist assumes it is, for the Sceptic the search for philosophical truth is the greatest impediment to the living of a good life. Secondly, the rejection of opinions does not leave the Sceptic without a criterion of action: in his tranquil state the Sceptic still goes along with appearances and remains actively engaged in the world. Finally, however, a response to the Essential Problem must satisfy the practical condition and provide a criterion for action without introducing a problematic claim to p-know anything. However the Sceptic comes to the view that he must go along with appearances in order to achieve happiness, it cannot be on the basis of a claim to (p-)know what things are really like (in their essential nature). It is not possible to reconstruct any response Pyrrho might have made to this problem, but that need not concern us here as Pyrrho's successors did address it. We can get a preliminary understanding of what this involves by looking briefly at what prompted the emergence of the school of Academic Scepticism. This began around 270 BCE, when Arcesilaus became Head of the Academy, some seventy-five years after the death of its founder Plato. At that time two rival schools dominated Athenian philosophy, Epicureanism and Stoicism. Stoicism developed around 300 BCE when Zeno (c. 350-258 BCE) took to frequenting the painted porch (stoa) in the Agora;5 its competitor a few years later when Epicurus (c. 341270 BCE), recently returned to Athens, constituted a kind of alternative philosophical community in the garden of his house. Naturally, the rivals held contrary positions on the most important philosophical issues. First the Epicureans: • Answer to the constitutive question: all that exists is an infinite number of indivisible atoms and the void through which they move: "Substance is divided" (II. 5). • Answer to the hypothetical question: we can have knowledge since all 'natural' phenomena can be explained mechanistically, without recourse to a divine plan ("God does not show providence for things in the universe" (ibid.)).

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• Answer to the normative question: "Pleasure is the beginning and end of the blessed life. For we recognize pleasure as the good which is primary and congenital . . . the feeling [is] the yardstick for judging every good thing" (Epicurus, 2IB). Now the Stoics: • Answer to the constitutive question: matter is a passive, undivided and unqualified plenum that is pervaded by reason (/ogos), God or cause (sometimes referred to as the 'worldsoul') which gives it its determinate characteristics and its historical shape. • Answer to the hypothetical question: we can have infallible knowledge since "Nature has given the sensory faculty and the impression which arises thereby as our light, as it were, for the recognition of truth" (Sextus, 40K). • Answer to the normative question: "Being happy . . . consists of living in accordance with virtue . . . in living in accordance with nature" (Stobaeus, 63A), "which is in accordance with the nature of oneself and that of the whole" (DL, 63C). Despite these rather profound differences, the contending schools shared the conviction that it is philosophy's ability to direct one in the acquisition of knowledge that qualifies it as the guide to living a happy life. To Arcesilaus, this represented a Dogmatic perversion of the Socratic legacy. It was the epistemology of the Stoics in particular that attracted his rancour. As Cicero (106-43 BCE) recounts: It was with Zeno .. . that Arcesilaus began his entire struggle . . . because of the obscurity of the things which had brought Socrates to an admission of ignorance . . . So Arcesilaus was in the practice of denying that anything could be known, not even the one thing Socrates had left for himself - the knowledge that he knew nothing: such was the extent of the obscurity in which everything lurked, on his assessment, and there was nothing which could be discerned or understood. For these reasons, he said, no one should maintain or assert anything or give it the acceptance of assent, but he should always curb his rashness and restrain it from every slip . . . He used to act consistently

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with this philosophy, and by arguing against everyone's opinions he drew most people away from their own, so that when reasons of equal weight were found on opposite sides on the same subject, the easier course was to withhold assent from either side. (Cicero, 68A) On the face of it, Cicero's summary presents us with a position not dissimilar to that we attributed to Pyrrho. There are, however, two important differences. First, Arcesilaus is reported as denying knowledge of the one thing that even Socrates was reported to know; namely, that he knew nothing. This sounds very much like the view Sextus used to characterize neo-Pyrrhonian Scepticism, and thereby distinguish it from Academic Scepticism. At the very least this suggests that Sextus's taxonomy is overly simplified, and that the Academic Sceptic cannot be straightforwardly dismissed as claiming to p-know that things cannot be known. The second difference relates to the detail we are given of Arcesilaus's method. This suggests a link between the 'way' in which Socrates arrived at his 'admission of ignorance' and Arcesilaus's explicit engagement with the opinions of the Dogmatists of his own time. In Plato's early dialogues Socrates is to be found seeking out particular interlocutors who claim to possess knowledge of what, for example, piety, courage or friendship are. In the course of public discussion, these views and others that are raised along the way are subjected to criticism, and the conclusion is invariably that none of those present - Socrates included - can justify their definition of a particular virtue.6 The participants are thus led to awareness that they don't in fact know what the virtue in question 'is', and that this knowledge of ignorance is preferable to the ignorance of ignorance. As we saw with Pyrrho, this awareness of ignorance can be thought of as a cognitive achievement, constituting /7-knowledge. Taken in this way it seems to lead the Sceptic to a self-defeating impasse. As we've also seen, however, knowledge for the Greeks is not to be understood simply on the model of propositional knowledge - it is better understood as a sort of ability or know-how. Indeed, even for Pyrrho, going along with appearances equips us with the ability to act in the world. This suggests a possible response to the Essential Problem: can we make sense of there being a way of coming to 'know' that (or of a path to it 'being apparent to us' that)

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we know nothing? If the path to - or method by which one could arrive at - such a state can be made intelligible, the Sceptic might be able to respond to the theoretical condition without undermining the distinction between the apparent and the non-apparent, and thus retain the former as a criterion for action. One influential attempt to move a little in this direction is by offering a 'dialectical interpretation' of Arcesilaus's views.7 We've already noted that an important aspect of Arcesilaus's approach was the willingness to engage with the Dogmatic theorists of his own time. The defining idea of Dogmatism is the conviction that philosophy can identify a criterion of truth: some indicator or mark that allows for the discrimination between what one should believe and do and what one shouldn't believe and do. As such, a criterion of truth - "something possessing the intrinsic power to convict falsehoods with truths" (Lucretius, 16A) - is the essential guide in the pursuit of the good life.8 For both Epicureans and Stoics all knowledge (including p-knowledge) is ultimately derived from experience, so the criterion is provided by the senses. According to the dialectical interpretation, then, the whole point of Arcesilaus's reasoning is not to advance any positive thesis about the nature of things, but is exhausted in the entirely negative project of 'deconstructing' the epistemological pretensions of the Stoics. To appreciate the dialectical interpretation and the extent to which it is successful in addressing the theoretical condition we therefore need to know a little more about the Dogmatisms that the Academics took such exception to. Before focusing our attention on the Stoics, let's turn briefly to their contemporaries, the Epicureans. Epicurean empiricism

According to Epicurus, sensation provides us with three criteria of truth: sensation itself, preconceptions and feelings.9 The first thing to note about sensations is that strictly speaking they are always 'true'; or, since this can sound confusing, they are always 'real'. To take a traditional example, although a barn may appear round from a distance and square up close, each image is - taken as such equally 'real'. In themselves, then, sensations are irrational passive, mechanical modifications of the body - and it is only judgements on or about them that constitute knowledge claims. These

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judgements utilize the second criterion of truth, prolepsis (preconceptions): general concepts that include not only ball, barn and leg, but also more abstract concepts like utility, the desirability of pleasure and even truth. When S judges that the barn is square or that the object is round she goes beyond the sensation itself and utilizes the appropriate concepts. Now it is evident that reasoning itself requires concepts, and the very possibility of philosophical knowledge is dependent on their having the status of criteria of truth. If they didn't possess the mark of truth the Epicureans couldn't claim to p-know that, for example, matter is divided and that pleasure is good. This suggests an obvious question: is the status of concepts as criteria of truth derived entirely from sensation, or does it depend upon non-empirical sources? An example of the latter would be something like Plato's theory of forms, where objective concepts (forms) are grasped by the mind. Since this conflicts with the resolutely empiricist standpoint of the Epicurean, that leaves only the former option: concepts are criteria of truth because they have been abstracted from or otherwise synthesized out of sensations of the appropriate sort. The sensations from which concepts that are to serve as criteria of truth ought to be abstracted are obviously sensations that are true. However, if all sensations are 'true' in the sense that they are real, this is not the sort of 'truth' required to justify the use of the concepts needed for knowledge (particularly p-knowledge) claims. It therefore appears that the Epicurean is committed to the view that sensations must incorporate some rational component that would warrant a judgement that things are a certain way. The upshot of this is that some sensations must be representative of their objects. Moreover, since the concept of truth is itself derived from true sensations, these must present themselves as being self-evidently true. That is to say, whatever feature characterizes the sensations that are representative of their objects (true), it must reveal itself as the mark of truth. By way of an illustration consider a book, optimistically entitled The Philosophical Guide to the Good Life and How to Live It. It contains a long (perhaps infinite) list of sentences (q2 to qn), some of which are true and some of which are false. The book's introduction informs S that if she discovers a foolproof way of distinguishing the true from the false she will get to live the good life. What S wants, then, is a criterion of truth. For the Epicureans, the sensations that are

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representative of their objects are analogous to the true sentences. When S reads (g901) Listening to Kylie will ruin your mind, or (qll9) Landlord is a fine pint of ale they will strike her as being self-evidently true. Moreover, she will see what it is about them that marks them out as being self-evidently true. Let's say that in this case it is the fact that they are oddnumbered sentences, allowing her to explicitly formulate the criterion of truth, and complete the book with: (q^

All and only the odd-numbered sentences in the book are true.

With this, S's philosophical work would be over and her future fame and fortune assured! Of course, the analogy only works if we can assimilate the Epicurean's sensations to sentences that are meaningful to S, and strictly speaking sensations are irrational. The closest analogy, then, is for q2 to qn to be written in a language S cannot understand. But suppose that in looking at g901 and qn9 S nevertheless still 'sees' that they are true and that they are true because they are odd-numbered, even though she doesn't know what either of them means. The point is that the sentences must be meaningful to S if they are to furnish her with the criterion of truth; which is to say, the Epicurean's sensations must themselves have a rational content such that those that are true reveal themselves as self-evidently true. Stoic empiricism

The Epicurean formulation of criteria of truth was the startingpoint for early Stoic epistemology. However, given the difficulties that issue from trying to make sense of the claim that sensations are irrational in their nature, we can appreciate what motivated their own divergent answers to our three questions. The upshot of the answer to the constitutive question is that where reason (logos) or the 'world soul' pervades matter and gives intelligible shape to nature, the individual soul pervades the body and provides its

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rational pattern. The fact that nature and ourselves as part of nature share a common rational structure ensures that the world is as it were apt for our knowing. On this account reason is not external to nature and so sensations are not 'external' to reason. They are not passive (mechanical), uninterpreted modifications of our body but take place in what is called the hegemonikon or commanding faculty (the highest part of the soul). Sensations thus have something like propositional content: they indicate that things are a certain way. Taking the example of the barn, when S has an impression that it is round, S has a thought with that content: she can say that the barn appears to be round or looks round. To undergo an impression is thus to engage in a rational activity; but that still leaves it open to the percipient to assent to the content of the impression or to refrain from doing so. Recalling our book analogy, the fact that impressions are internal to reason means that the propositions q2 to qn are guaranteed to be intelligible: we can understand their meaning. Taken in isolation that does not indicate that we should believe what they say. If S reads that the barn is round S can fully understand the claim and still refuse to assent to it. Of course, this assent is precisely that step beyond appearances and to a claim about how things really are that Pyrrho denied one should take. It does however demonstrate how Stoic epistemology links up with the idea of action oriented towards living the good life. If S assents to an appearance she takes cognitive responsibility for the belief that (say) the barn is round. This application of the term is distinct from the one we associated with Pyrrho, for on the Stoic account this belief will be either true or false (the barn really is round or not). Moreover, responsibility to the truth is not to be understood as being merely theoretical. Since knowledge is indeed possible on the basis of the Stoic's answer to the constitutive question, the key to happiness is given by the answer to the normative question. The responsibility at issue amounts to the obligation to shape one's patterns of assent in such a way that one lives in accordance with one's own nature, and with nature as a whole. To live the Stoic version of the good life is to rationally harmonize one's soul with the world soul, and this requires that one know when to assent and when not to - possesses, as it were, a key to identifying which propositions in the book are true and which are

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false. In other words, one needs a criterion of truth.10 For the Stoics this was provided by the 'cognitive impression' (phantasia kataleptike). As initially formulated, this had to satisfy two conditions: (A) It has a real object as its cause: it "arises from what is" (Sextus, 40E). (B) It represents its object clearly and distinctly: it is "stamped and impressed exactly in accordance with what is" (ibid.). As Arcesilaus is reported to have pointed out, (A) and (B) do not alone constitute a criterion of truth. If S cannot distinguish between a genuine perception of a barn and a barn-hallucination in so far as she is unable to discern which one represents its real object (the real object of the hallucination being oneself), the clarity and distinctness of the presentation of an object in an impression is not the criterion of truth. To rescue the concept of the cognitive impression Zeno therefore added a third condition: (C) The clarity and distinctness of the impression are functions of how things really are: the impression is "of such a kind that could not arise from what is not" (ibid.) What (C) adds is the claim that if I am presented with an impression of a round barn, that impression could only be clear and distinct if it were caused by a round barn, and not (say) by myself (as in a dream or hallucination). Arcesilaus remained unconvinced. He deployed a number of examples to challenge (C), seeking to demonstrate that no impression arising from something true ('what is') has a property such that it could be distinguished from one arising from something false ('what is not'). In other words, although an impression might clearly and distinctly represent its object, it does not in addition carry a label that provides a subjective guarantee that it does so. It does not as it were carry a passport containing a photo of the object it represents! In contemporary terms, Arcesilaus is attacking the Stoic's internalist account of justification. The criterion of truth is the basis of any attempt to shape one's life in accordance with reason in pursuit of happiness. In the absence of a criterion of truth the distinction between a justified belief (or action) and an unjustified

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belief collapses and there is no rational guide to how to live one's life. We'll return to this line of criticism below but it should be noted that the Stoic does have a response. He points out that while S might mistakenly assent to a barn-hallucination, that does not in itself undermine the idea that the cognitive impression serves as a criterion of truth. Rather, it demonstrates that S lacks the disciplinecum-wisdom required to ensure that she only ever assents to impressions that are genuinely cognitive and withholds assent in other cases. So who does have the necessary discipline and wisdom? Cognition and knowledge For the Stoic the cognitive impression is our guide to the recognition of truth. Since the cognitive impression arises as a result of our sensory faculty, it is common to human beings - we all have this natural capacity to 'track' the truth. As Sextus also notes, "this impression, being self-evident and striking, all but seizes us by the hair. . . and pulls us to assent" (40K). So we all have the capacity to recognize truths as truths - they are the ones that 'pull us to assent' (propositions we read that overwhelm us with their self-evident truth). And this is all as it should be: the good life is the good life for any human being, and Stoic philosophy is the guide to achieving it. As we saw above, however, the Stoic defence of the cognitive impression - and thus of the distinction between being justified and not being justified in living a certain way - seems to rest on the distinction between the wise (disciplined) and the unwise (undisciplined). What are we to make of this distinction? The answer lies in the fact that the impression 'all but' seizes us by the hair. If it were the case that by definition any and all cognitive impressions literally and absolutely convinced us of their truth, it would be impossible to see how anyone could ever make an erroneous judgement or act in an undisciplined or cognitively irresponsible way.11 In such a situation, a criterion of truth wouldn't be a criterion at all and the concept of the good (as opposed to any other) kind of life would disappear, along with any role for philosophy (and reflection generally). The 'all but' indicates that there is a 'gap' between the impression and the assent such that one could fail to assent to even a 'cognitive impression'. To modernize an example used by Sextus

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(40K), imagine that S saw a friend die in hospital, and a week later he appears before her in the street (he'd been in a vegetative state, mistaken for death at the time). Here S undergoes a cognitive impression, but, reasoning that her friend can't be alive, withholds assent. In order for the cognitive impression to carry out its criteria! function, then, there must be nothing in the context of apprehension that constitutes an impediment to it being taken as such (this includes the mental state of the percipient). This does not exhaust the significance of that 'gap', however. It turns out that even if S undergoes and assents to a cognitive impression in a context that presents no impediment to grasping its clarity and distinctness, she still does not qualify as wise as opposed to ignorant because this does not amount to knowledge proper (episteme), but only to cognition (katalepsis). We therefore have the following hierarchy: doxa (opinion), katalepsis (cognition) and episteme (knowledge). For the Stoics, doxa are beliefs that arise from assenting to the 'incognitive' - to what is either false or not 'clear and distinct'.12 Katalepsis refers to those beliefs that result from assenting to a cognitive impression, and therefore approximate to the contemporary epistemologist's justified true beliefs. In our book example doxa would be propositions in the book that S assents to and which are false, whereas katalepsis would result from assenting to a self-evidently true proposition. To appreciate the distinction between katalepsis and episteme, recall that cognitive impressions are 'caused' by their appropriate objects (C). The content of the impression - what makes it the kind of impression it is - is thus determined by the way the world is. Assent to any particular cognitive impression does not amount to knowledge in the full sense because as such it has no implications for one's responses to other impressions. S might rightly assent to q901 but also (erroneously) to (say)